feat: add relay status indicator for local-only/offline mode

- Create RelayStatusIndicator component with plane icon for local-only mode
- Position indicator in bottom-left corner with amber styling
- Show when only local relays are connected or completely offline
- Hide indicator when remote relays are available (normal operation)
- Add pulsing globe icon animation to indicate checking for connection
- Include hover effects and smooth transitions
- Auto-adjust position when sidebar is collapsed
- Display relay count and clear status messages

src/components/RelayStatusIndicator.tsx

@@ -0,0 +1,60 @@
+import React from 'react'
+import { FontAwesomeIcon } from '@fortawesome/react-fontawesome'
+import { faPlane, faGlobe, faCircle } from '@fortawesome/free-solid-svg-icons'
+import { RelayPool } from 'applesauce-relay'
+import { useRelayStatus } from '../hooks/useRelayStatus'
+import { isLocalRelay } from '../utils/helpers'
+
+interface RelayStatusIndicatorProps {
+  relayPool: RelayPool | null
+}
+
+export const RelayStatusIndicator: React.FC<RelayStatusIndicatorProps> = ({ relayPool }) => {
+  const relayStatuses = useRelayStatus({ relayPool, pollingInterval: 3000 })
+  
+  if (!relayPool) return null
+  
+  // Get currently connected relays
+  const connectedRelays = relayStatuses.filter(r => r.isInPool)
+  const connectedUrls = connectedRelays.map(r => r.url)
+  
+  // Determine connection status
+  const hasLocalRelay = connectedUrls.some(url => isLocalRelay(url))
+  const hasRemoteRelay = connectedUrls.some(url => !isLocalRelay(url))
+  const localOnlyMode = hasLocalRelay && !hasRemoteRelay
+  const offlineMode = connectedUrls.length === 0
+  
+  // Don't show indicator when fully connected
+  if (!localOnlyMode && !offlineMode) return null
+  
+  return (
+    <div className="relay-status-indicator" title={
+      offlineMode 
+        ? 'Offline - No relays connected'
+        : 'Local Relays Only - Highlights will be marked as local'
+    }>
+      <div className="relay-status-icon">
+        <FontAwesomeIcon icon={offlineMode ? faCircle : faPlane} />
+      </div>
+      <div className="relay-status-text">
+        {offlineMode ? (
+          <>
+            <span className="relay-status-title">Offline</span>
+            <span className="relay-status-subtitle">No relays connected</span>
+          </>
+        ) : (
+          <>
+            <span className="relay-status-title">Local Only</span>
+            <span className="relay-status-subtitle">{connectedUrls.length} local relay{connectedUrls.length !== 1 ? 's' : ''}</span>
+          </>
+        )}
+      </div>
+      {!offlineMode && (
+        <div className="relay-status-pulse">
+          <FontAwesomeIcon icon={faGlobe} className="pulse-icon" />
+        </div>
+      )}
+    </div>
+  )
+}
+

src/components/ThreePaneLayout.tsx

@@ -6,6 +6,7 @@ import { HighlightsPanel } from './HighlightsPanel'
 import Settings from './Settings'
 import Toast from './Toast'
 import { HighlightButton } from './HighlightButton'
+import { RelayStatusIndicator } from './RelayStatusIndicator'
 import { ViewMode } from './Bookmarks'
 import { Bookmark } from '../types/bookmarks'
 import { Highlight } from '../types/highlights'
@@ -149,6 +150,7 @@ const ThreePaneLayout: React.FC<ThreePaneLayoutProps> = (props) => {
           highlightColor={props.settings.highlightColor || '#ffff00'}
         />
       )}
+      <RelayStatusIndicator relayPool={props.relayPool} />
       {props.toastMessage && (
         <Toast
           message={props.toastMessage}

src/index.css

@@ -2426,3 +2426,84 @@ body {
   opacity: 0.6;
   cursor: not-allowed;
 }
+
+/* Relay Status Indicator */
+.relay-status-indicator {
+  position: fixed;
+  bottom: 1.5rem;
+  left: 1.5rem;
+  z-index: 999;
+  display: flex;
+  align-items: center;
+  gap: 0.75rem;
+  padding: 0.75rem 1rem;
+  background: rgba(245, 158, 11, 0.95);
+  border: 1px solid rgba(245, 158, 11, 0.4);
+  border-radius: 8px;
+  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
+  backdrop-filter: blur(10px);
+  transition: all 0.3s ease;
+  cursor: default;
+}
+
+.relay-status-indicator:hover {
+  background: rgba(245, 158, 11, 1);
+  transform: translateY(-2px);
+  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.4);
+}
+
+.relay-status-icon {
+  font-size: 1.25rem;
+  color: #1a1a1a;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+}
+
+.relay-status-text {
+  display: flex;
+  flex-direction: column;
+  gap: 0.15rem;
+}
+
+.relay-status-title {
+  font-size: 0.875rem;
+  font-weight: 600;
+  color: #1a1a1a;
+  line-height: 1.2;
+}
+
+.relay-status-subtitle {
+  font-size: 0.75rem;
+  color: rgba(26, 26, 26, 0.8);
+  line-height: 1.2;
+}
+
+.relay-status-pulse {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  margin-left: 0.25rem;
+}
+
+.pulse-icon {
+  font-size: 0.875rem;
+  color: rgba(26, 26, 26, 0.6);
+  animation: pulse 2s ease-in-out infinite;
+}
+
+@keyframes pulse {
+  0%, 100% {
+    opacity: 0.4;
+    transform: scale(1);
+  }
+  50% {
+    opacity: 1;
+    transform: scale(1.1);
+  }
+}
+
+/* Adjust for collapsed sidebar */
+.three-pane.sidebar-collapsed .relay-status-indicator {
+  left: calc(var(--sidebar-collapsed-width) + 1.5rem);
+}